(a) Field
The present application relates to a display device. More particularly, the present application relates to a display device capable of being driven with low power.
(b) Description of the Related Art
A display device such as a liquid crystal display (LCD), an organic light emitting diode display, or the like, generally includes a display panel including a plurality of pixels and a plurality of signal lines and a driving unit driving the display panel. The respective pixels include switching elements connected to the signal lines, pixel electrodes connected to the switching elements, and counter electrodes. The driving unit includes a gate driver supplying gate signals to the display panel, a data driver supplying data signals to the display panel, a signal controller controlling the data driver and the gate driver, and the like.
The pixel electrodes are connected to the switching elements such as thin film transistors (TFTs), or the like, to receive data voltages. The counter electrodes are formed over an entire surface of the display panel, and may receive a common voltage Vcom applied thereto. The pixel electrodes and the counter electrodes may be positioned on the same substrate or be positioned on different substrates.
For example, the liquid crystal display includes two display panels including the pixel electrodes and the counter electrodes and a liquid crystal layer disposed between the two display panels and having dielectric anisotropy. The pixel electrodes are arrange in a matrix form and are connected to the switching elements such as thin film transistors (TFTs), or the like, to sequentially receive the data voltage row by row. The counter electrodes are formed over the entire surface of the display panel, and receive the common voltage Vcom applied thereto. Voltages are applied to the pixel electrodes and the counter electrodes to generate an electric field in the liquid crystal layer, and the strength of the electric field is adjusted to adjust transmittance of light passing through the liquid crystal layer, thereby making it possible to obtain a desired image.
The display device receives an input image signal from an external graphic controller, wherein the input image signal includes luminance information of each pixel, and each luminance has a predetermined number of grays. Each pixel receives data voltages corresponding to desired luminance information. The data voltages applied to the pixels appear as pixel voltages depending on differences between the data voltages and a common voltage applied to a common electrode, and each pixel displays luminance representing a gray of an image signal depending on pixel voltages. Here, in the case of the liquid crystal display, in order to prevent a degradation phenomenon generated when the electric field in one direction is applied to the liquid crystal layer for a long time, polarities of data voltages for a reference voltage may be inverted for each frame, each row, each column, and each pixel. In addition, in order to decrease power consumption of the display device, data voltages having different polarities may be applied to each column.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.